Lexus IS C (convertible) key fob battery
3 of the 6 model years listed for the Lexus IS C (convertible) have a proven battery. The most common answer is CR1632. Rows below run oldest to newest; a year can appear twice when the car came with more than one kind of key.
- 2010-2012Smart key
CR1632
FCC ID HYQ14AEMTwo sites agree: uhs-hardware.com and bestkeysupply.com (checked Nov 2, 2026)
Find CR1632 on Amazon - 2013-2015Smart key
Not confirmed yet
Changing the battery
Smart key (push-button start)
- Most push-button fobs hide a metal backup key. Press or slide its catch and draw the key out first.
- Look inside the empty key slot for a notch. Put the tip of the metal key or a small flat screwdriver wrapped in tape there and twist gently until the shell splits.
- Pop the old battery out with a toothpick or plastic pick, not a metal blade, and seat the new one with the + side matching the old one.
- Snap the halves back together, slide the metal key home, and press each button, then try the start button from the driver's seat.
Lexus smart keys usually hide the metal key behind a release button; the cover opens from the notch next to where the key sat.
A CR1632 is 16 mm across and 3.2 mm thick. It is easy to confuse with the 20 mm CR20xx sizes, which will not fit.
If a child might have swallowed a coin cell, treat it as an emergency and get to a hospital right away.